None of my math instructors at MIT ever looked like her: The NY Times has an excellent profile of actress Danica McKellar, who played Winnie on The Wonder Years. Some excerpts:

Ms. McKellar, now a semiregular on "The West Wing" playing a White House speechwriter, Elsie Snuffin, is probably the only person on prime-time television who moonlights as a cyberspace math tutor.

Her mathematics knowledge extends well beyond calculus. As a math major at the University of California, Los Angeles, she also took more esoteric classes, the ones with names like "complex analysis" and "real analysis," and she pondered making a career move to professional mathematician.

She may also be the only actress, now or ever, to prove a new mathematical theorem, one that bears her name. Certainly, she is the only theorem prover who appears wearing black lingerie in the July issue of Stuff magazine. Even in that interview, she mentioned math.

Those who want to know more about the Chayes-McKellar-Winn theorem can read her paper, "Percolation and Gibbs States Multiplicity for Ferromagnetic Ashkin-Teller Models on Z^2".

(Via Tom McMahon.)